鳡鱼池塘养殖技术

鳡鱼(Elopichthys bambusa)是江、湖野生的名优鱼类之一，属鲤形目、鲤科、雅罗鱼亚科鱼类，俗称黄鲇，它长速快，个体大，病害少，市场价格高。2003年我们在吴江市特种水产科研示范园区进行了鳡鱼的池塘养殖试验。现将试验情况介绍如下。     

绥芬河滩头雅罗鱼溯河生殖群体结构的探讨

本文报道绥芬河鲤科唯一溯河性洄游鱼类滩头雅罗鱼生殖群体生物学。通过１，７９３尾样品测定，对溯河期，产卵期，群体的年龄生长，体长体重，生殖力，性比，成熟系数，肥满度等主要生态学特征及种群数量作了研究。为开发，增殖这一稀有经济鱼类资源提供重要的生物学资料。     

脂类和维生素对鱼类生殖的影响

营养素作为影响鱼类生殖全过程的一种外部因素，对亲鱼的生殖力和卵子质量等具有重要作用。综述了近年来国内外有关营养素与鱼类生殖的研究概况，详细阐述了脂类和维生素对鱼类生殖的影响。     

筑坝河流鱼类生物完整性研究——以珠江流域红水河为例[收稿日期：2021-08-30

基于红水河流域开发特点和鱼类群聚组成特征，构建红水河鱼类生物完整性评价指标体系，评价梯级开发对红水河不同生境类型的鱼类生物完整性的影响。河流参照状态和基准值由1982—1994年鱼类历史监测数据分析得到；监测值是2013年调查的鱼类数据；现状值为2018年鱼类数据。针对红水河鱼类区系特点和高强度水电开发特征，选取总种类数占期望值比例、鲤科鱼类所占比例、鲿科鱼类所占比例、鲇科鱼类所占比例、耐受性鱼类个体所占比例、渔获物中出现的科数所占比例、杂食性鱼类个体所占比例、底栖动物食性鱼类个体所占比例、顶级肉食性鱼类所占比例和外来种个体所占比例等10个指标构建红水河IBI指标体系。结果表明：2013年25个采样江段的IBI值为38 ~ 80分，均值62分。其中，24%的江段生物完整性等级为“好”；32%的江段生物完整性等级为“一般”；44%的江段生物完整性等级为“差”。从生境类型来看，支流生物完整性明显优于水库、库尾回水区。此外，现状数据评价的结果为：2018年红水河IBI值为64分，高于2013年均值62分，生物完整性均处于“一般”等级。     

斑点叉尾鲴的养殖技术

斑点叉尾鲴，又称沟鲇、河鲇，属于硬骨鱼纲鲇形目鲴科。原产于美洲，广泛分布于美洲中部、东部的淡水和咸水中．是从美国引进的名贵淡水经济鱼类品种。该鱼具有肉质细嫩、味道鲜美、无肌间刺、营养丰富（蛋白质含量很高．而且不饱和脂肪酸含量高）、生长快、个体大、抗病力强、适应性强等特点。     

丝鳍海鲇网箱养殖和越冬试验

<正>丝鳍海鲇(Arius arius)为常见的暖水性近海底层鱼类，隶属于鲇形目，海鲇科，海鲇属。分布于我国黄海南部、东海和南海，是我国沿海捕捞经济鱼类品种之一。丝鳍海鲇生活在水流缓慢的泥质海底，每年的生殖季节，结成大群，由深水游向沿岸和河口浅水区表层，产卵繁殖^[1]。在浙南温州，丝鳍海鲇俗称王鱼，王鱼烧粉干为当地有名的特色菜。     

东海带鱼Trichiurus haumela(Forskal)个体生殖力的研究

鱼类生殖力的研究是分析种群数量变动的重要环节之一,特别是与补充群体的联系最为密切。此外,生殖力指标及其变动规律也是探讨鱼类种群特征的重要资料。 带鱼是我国最主要的海产经济鱼类之一,近年来产量一直居于首位。但对其个体生殖力的研究还很少,仅在某些综合性的研究报告中有些零星记载,以此作为探索带鱼种群数量变动规律的生物学基础资料是不够的。本文就东海近海所采集的部分带鱼卵巢标本,对它的个体生殖力的变动规律及特点等进行了初步分析和讨论,希望得到批评、指正。     

东海带鱼Trichiurus haumela(Forsk(?)l)个体生殖力的研究

鱼类生殖力的研究是分析种群数量变动的重要环节之一,特别是与补充群体的联系最为密切。此外,生殖力指标及其变动规律也是探讨鱼类种群特征的重要资料。 带鱼是我国最主要的海产经济鱼类之一,近年来产量一直居于首位。但对其个体生殖力的研究还很少,仅在某些综合性的研究报告中有些零星记载,以此作为探索带鱼种群数量变动规律的生物学基础资料是不够的。本文就东海近海所采集的部分带鱼卵巢标本,对它的个体生殖力的变动规律及特点等进行了初步分析和讨论,希望得到批评、指正。     

汤阴汤河国家湿地公园鱼类资源调查

2018年4月至2021年10月，对汤河国家湿地公园鱼类资源开展了调查。结果表明，收集到鱼类23种，隶属于4目7科22属。其中鲤形目16种，占总种数的69.56%，鲈形目4种，鲇形目2种，分别占总种数的17.39%和8.69%，合鳃目1种，占总种数的4.36%，以鲤科种属最多，14属15种，占比65.22%；鱼类可划分为中国平原区系复合体、晚第三纪早期区系复合体、南方平原区系复合体和北方平原区系复合体。对鱼类种群特征、影响鱼类资源的因素等进行了分析。提出，为了更好地保护恢复鱼类资源，应优化增殖种类；规范鱼类引种；打击非法捕鱼；截污，保证下游汤河生态流量；增放人工鱼巢，提高幼鱼种群量；科学动态监测，维护汤河国家湿地公园生态系统的多样性、稳定性和持续性。     

南方鲇的饲料营养

南方鲇（Silurus metidionalis Chen）原名南方大口鲇，俗称河鲇、大口鲇等，隶属于鲇形目，鲇科，鲇属。该鲇广泛分布于我国长江及其以南的江河，是一种肉食性的大型名贵经济鱼类。南方鲇的含肉率高达61．07％，     

Prevalence of nematode parasite,Contracaecum, in Nile tilapia,African catfish and Barbus species in Lake Hawassa,Ethiopia

A cross‐sectional study was conducted from November 2017 to March 2018 at Lake Hawassa to determine the prevalence of larval Contracaecum infestation in Nile tilapia, (Oreochromis niloticus), African Catfish (Clarias gariepinus) and Barbus species (Barbus intermedius). Fifty‐two point six per cent (52.6%) previous prevalence and 5% precision were used to estimate the sample size. Accordingly, a total of 383 randomly sampled fish species comprising of 163 (42.6%) C. gariepinus, 159 (41.5%) O. niloticus and 61(15.9%) B. intermedius were examined. The length and weight of each sampled fish were recorded. All the sampled fish were examined for the evidence of Contracaecum parasites in Hawassa University Veterinary Parasitology and Pathology Laboratory. Chi‐square values and comparison of proportions were used to analyse the data. The overall prevalence of Contracaecum parasites of fish population was 31.6%. The distribution of parasite was significantly affected by fish species (p = .000), sexes (p = .018), length (p = .003) and weight classes of fish (p = .026). As a hygienic problem and gutting activity conducted at the sides of the Lake Hawassa and distribution of discarded fish wastes for surrounding piscivorous birds by butchers and other people, the life cycle of Contracaecum parasite was perpetuated. Thus, the parasite is of zoonotic significance. Therefore, awareness creation activities for societies and control of fish parasites should be conducted in the study area.     

Recruitment strategy of swimming crab, Portunus trituberculatus, in Hiuchi-Nada, Japan

The recruitment strategy of swimming crabs, Portunus trituberculatus, was investigated by field observations and numerical experiments in Hiuchi-Nada, Japan. Calculated dispersal patterns of zoeal and megalopal stages in a three-dimensional numerical model reproduce observed patterns accurately. The temporal change of vertical migration patterns between the 1st and 2nd zoeas and the 3rd and 4th zoeas plays an important role in the process of recruitment of P. trituberculatus from spawning ground to nursery ground.     

Advance in the Culture Research of Small-Eye Flounder,Paralichthys microps,and Chilean Flounder,P. adspersus,in Chile

ABSTRACT

Over 71% of the aquaculture production of Chile is based on salmonids, and given the recents problems in the world salmon industry, it is necessary to investigate the culture of new species as a vital priority to maintain an industry of great social and economic impact for Chile. Small-eye flounder, Paralichthys microps, and chilean flounder P. adspersus, are native, high-value flatfish present off the coasts of Perú and Chile, that are commonly exploted by artisanal fishermen. Since 1986 both species have been objects of research studies for culture based on techniques developed for Japanese flounder. This paper is a review of current knowledge of this species and to identify research needs for the near future. Natural spawning of small-eye flounder and chilean flounder broodstock in captivity is already possible, but the manipulation of spawning using photoperiod and hormonal inducement, as well as the role of broodstock nutrition in egg and larval quality, needs to be explored. Successful incubation and larval culture protocol for both species have been developed, with larval survival over 24% from certain egg batches. Nutritional characterization and requirements for chilean flounder eggs and larvae during the culture period, optimal temperature, density, light intensity and green-water culture, are all subjects of ongoing research. Efforts to improve early culture protocol continues with emphasis on causes of larval mortality, early use of dry feed, microbial ecology of culture tanks and water quality. Weaning from live to formulated diets has been investigated, demonstrating survival of 30-50%. Presently only about 1-5% of hatchery raised flounder show a pigment disorder. Research on formulated diets and the weaning process are under way to ameliorate these results. Juveniles are being grown experimental in tanks and net pens systems and their performance (growth, survival, health) in both systems is being evaluated. Chilean flounder require approximately 2.8 years to reach 1 kg. Effort is also focusing on improving juvenile growing protocol, including recirculation systems, culture environment and diet formulation. Much future research will be required to attain optimal production of the species, such as species-specific nutritional requirements, optimum stocking density, disease and health management and growing protocols with new systems (shallow raceway). At present there is enough known about chilean flounder to begin a pilot-stage that will be the key for future development of its culture.     

Stocking of sea trout, Salmo trutta, in Lake Veere, south-west Netherlands

Lake Veere (1750–2050 ha), a brackish water lake in south‐west Netherlands, is a former branch of the Oosterschelde. The lake was closed off by the construction of two dams in 1961. Since the early 1970s Lake Veere has been regularly stocked for recreational and commercial fisheries with rainbow trout, Oncorhynchus mykiss (Walbaum), brown trout, Salmo trutta L., and glass eel, Anguilla anguilla (L.). Between May and September 1996 an experimental stocking of 18 054 trout of sea trout parentage (15–16 cm; 776 kg) was carried out to study their potential for recreational fisheries. The growth and mortality of the stocked trout were estimated from recaptures in eel fyke nets. The production and consumption of the stocked trout were estimated with a bioenergetics model. After 3.5 years (May 1996–November 1999) the stocked trout measured between 50 and 70 cm. The estimated annual total mortality was 84%. During the winter of 1996–1997, the biomass of the stocked trout reached a maximum of about 1800 kg. By November 1999 the biomass was estimated to be 100 kg. The maximum daily consumption by the trout population was 60 g ha^?1 in October 1996 and in June 1997. The total consumption of the stocked trout population over the 3.5‐year period was estimated as 54 244 kg. The analysis suggested that the stocked trout used about 0.2% of the average annual primary production of the lake system. Although the growth and initial production of the population are attractive from the perspective of a recreational fishery, the high mortality and infestation with the salmon louse, Lepeophtheirus salmonis (Krøyer), are serious drawbacks for a future stocking programme with trout in Lake Veere.     

Low allozyme variation in snapper, Pagrus auratus, in Victoria, Australia

The population genetic structure of snapper, Pagrus auratus (Bloch and Schneider), in Victoria was investigated using six polymorphic allozyme loci. Fish were sampled from four sites in Victoria and single locations in South Australia, Western Australia and New Zealand. Although there were distinct genetic differences between the snapper populations from each of the Australian states and New Zealand, only minor and largely insignificant differences were detected among Victorian populations. The results are consistent with previous genetic and tagging studies that indicate no mixing between snapper stocks in Victoria and Spencer Gulf in South Australia. This justifies separate management of the snapper fisheries in these regions. The low levels of polymorphism and heterozygosity in Victorian snapper suggest an isolation by distance model of population structure rather than one of discrete subpopulations.     

Age,growth, maturity and the overfishing of the iconic sciaenid,Argyrosomus japonicus,in south-eastern,Australia

Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L₅₀ of 68 cm, whereas males matured at 2–3 years of age with a L₅₀ of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.     

Effect of Stocking Density on Growth,Yield, and Costs of Producing Rainbow Trout,Oncorhynchus mykiss,in Cages

Abstract

Rainbow trout, Oncorhynchus mykiss, were raised in culture cages (1 m³) to determine the effect of stocking density on growth, survival, and percentage of market-size fish. Large fingerling rainbow trout (20-25 cm, 232 g average weight) were stocked into six cages located in a 0.4-ha pond. Two stocking densities (100 or 200 fish/cage) were used, and fish were grown for 140 days (2000-April 2001). Average total harvest weight (35.0 kg) in the low-density cages was approximately one-half the average total harvest weight (61.2 kg) in the high-density cages. Average weight gain (11.7 kg to 15.1 kg) and feed conversion (1.2 to 1.5) were also smaller for the low-density cages. Average survival was 96.7% for the low-density cages and 94.2% for the high-density cages, with the percentage of market-size fish (< 29 cm) averaging 50.3% and 52.0%, respectively. Production costs for the actual experiment and the revenues from fish sold at the end of the study were collected. An enterprise budget based on the experimental results for the two densities was developed to determine if a culture operation of this size would produce a net return. Production costs and revenues from the experiment resulted in a large negative return (-$3,124) and high breakeven price ($13.53/kg).     

Status,ecology and conservation of an endemic fish,Oreochromis niloticus baringoensis,in Lake Baringo,Kenya

• 1. The tilapia Oreochromis niloticus baringoensis is a genetically and morphologically distinct sub‐species of Oreochromis niloticus endemic to Lake Baringo, Kenya. In recent years, concern has been expressed as to its status. Recent declines in catch returns suggest the population may be threatened, with conservation action required to safeguard it.
• 2. Catch returns from the Baringo fishery since 1964 have shown considerable fluctuations for all species, but especially O. n. baringoensis. From a peak of 712 t in 1970, their total catch was only 5 t in 2005, despite a 2 year period of closure in 2002 and 2003. Changes in fishery catch and relative abundance were independent of exploitation in the fishery but were significantly correlated with lake level.
• 3. Few individuals were captured at lengths >250 mm, with no fish sampled >284 mm. During periods of high lake level, individuals matured at smaller sizes and were capable of growing to larger ultimate sizes. With maturity at lengths <130 mm and fishery regulations preventing removal of fish <180 mm, there was a relatively large proportion of mature fish that was below exploitation size each year (19 to 44%). In most years, the proportion of fish available for exploitation was <10%.
• 4. Stable isotope analyses revealed O. n. baringoensis was reliant upon planktonic basal resources and zooplankton carbon. There was only minimal trophic overlap with other fish species in the lake, indicating little potential for competition for food resources.
• 5. These data suggest that the population status of O. n. baringoensis is not threatened per se, but subject to an unpredictable and unstable environment that strongly influences their life‐history traits and, ultimately, their population abundance, and should be managed accordingly.

Copyright © 2008 John Wiley & Sons, Ltd.     

碧流河水库陆封型香鱼生物学特性的演变

1982年碧流河水库建成后，被陆封在水库中的香鱼（Plecoglossus altivelis)经10余年适应后，其生物学特性发生了很大变化，其中一部分个体春季水温上升后暂不进入河道，而留在水库中生活，至7月份才进入河道，与刚陆封时不同，在其植物食性阶段，消化道内有大量浮游植物出现，繁殖期也由9－10月提前到8－9月，性腺发育速度明显加快，个体进一步变小。